Don't think you will get a consensus of opinion on this.. Horn use is dependent on the work environment. Some operations are very noisy - like stamping and forging operations and ear plugs may be requireds. Some operators just want to be obnoxious on certain days and like to express this to the world. Have seen operations where electric forklift are used and they put bell ring in the steering wheel hub to make a noise as the forklift are too quiet. Some folks install beepers on the lift any time the lift is moving.

Good Luck in you task.